A re-evaluation of Scinaia (Nemaliales, Rhodophyta) in the Azores

Helgol Mar Res (2011) 65:111–121 DOI 10.1007/s10152-010-0207-2 O R I G I N A L A R T I CL E A re-evaluation of Scinaia (Nemaliales, Rhodophyta) in the Azores K. León-Cisneros · R. Riosmena-Rodríguez · A. I. Neto Received: 8 July 2009 / Revised: 3 May 2010 / Accepted: 12 May 2010 / Published online: 25 May 2010 © Springer-Verlag and AWI 2010 Abstract The genus Scinaia in the Azores is re-evaluated based on historical and recent collections. A combination of morphological and anatomical diagnostic characters was used for species segregation, and a key for Azorean species determination is presented. Anatomical information associated to the hair development is described for the Wrst time for the genus. The occurrence of S. furcellata and S. interrupta is conWrmed for the archipelago. The presence of S. acuta is reported for the Wrst time in the Azores, representing a spread from Australia to the N-Atlantic and speciWcally into the Macaronesian region. Its occurrence in the archipelago and the Canaries is discussed as a possible introduction. Keywords Anatomy · Azores · Morphology · Nemaliales · Scinaia · Taxonomy Communicated by Inka Bartsch. K. León-Cisneros (&) · R. Riosmena-Rodríguez Programa de Investigación en Botánica Marina, Universidad Autónoma de Baja California Sur, Apartado Postal 19-B, CP 23080 La Paz, BCS, Mexico e-mail: K. León-Cisneros · A. I. Neto CIIMAR (Centro Interdisciplinar de Investigação Marinha e Ambiental), Universidade do Porto, Rua dos Bragas, 289-4050-123 Porto, Portugal K. León-Cisneros · A. I. Neto Secção de Biologia Marinha, Departamento de Biologia, Universidade dos Açores, Campus de Ponta Delgada, Apartado 1422, 9501-801 Ponta Delgada, Açores, Portugal Introduction The genus Scinaia (Nemaliales, Scinaiaceae, Huisman et al. 2004) was established by Bivona-Bernardi (1822) based on Scinaia forcellata, which is now known as S. furcellata (Turner) J. Agardh (for name review see Silva 1992: p. 167 and Silva et al. 1996: p. 114). Widely distributed around the world (Guiry and Guiry 2009), this genus encompasses 43 species, most of them incompletely described. It has been investigated in NW Europe (Maggs and Guiry 1982), Australia (Huisman 1986, 2006; Millar 1990; Huisman and Womersley 1994), Japan (Kajimura 1988, 1991, 1995), Korea (Lee and Ko 2006) and the Gulf of California (León-Cisneros et al. 2009). These authors described the morphological, anatomical and reproductive features used for species diagnosis. The evolutionary scheme proposed by Huisman (1986) encompassing four groups—‘Scinaia complanata group’, ‘Scinaia moniliformis group’, ‘Scinaia carnosa group’ and ‘Scinaia furcellata group’—was not followed by Kajimura (1995), but he also did not propose an alternative scheme. Two species of Scinaia have been recorded for the Azores (Neto 1994): Scinaia furcellata, Wrstly cited for Terceira island by Schmidt (1929), and S. interrupta (A. P. de Candolle) M. J. Wynne, Wrst recorded for the islands of Faial, São Jorge and Pico by Fredericq et al. (1992). The diagnosis of these species was based mainly on external morphological characters, and the genus has not been studied in the Azores since 1994. In the present study, a re-evaluation of the genus in the area is made, based on recent collections, herbarium material and historical collections, including type specimens. A critical re-assessment of vegetative and reproductive features suitable for species determination is made, and an account of the species identiWed in the area is provided. 123 112 Materials and methods Studied material included fresh collections, historical collections borrowed from AZB and BM, and type material borrowed from BM (herbarium abbreviations as in Holmgren and Holmgren 1998). Fresh specimens were collected intertidally and subtidally (by scuba diving to 30 m depth) during Weld surveys in the Azores archipelago (Fig. 1) between 2006 and 2008. Samples were Wxed in 5% buVered formalin in seawater or pressed following standard protocols and housed at AZB (herbarium of the University of the Azores). For morphological and anatomical studies, herbarium material was re-hydrated using a saturated detergent solution in warm water. For anatomical examination, semipermanent microslides were prepared by mounting thin hand-sections of the thallus in 50% corn syrup (Karo Best Foods, Englewood CliVs, USA), after staining in 1% aniline blue. Measurements of cells and other taxonomically relevant structures were carried out using a calibrated micrometer eyepiece. Photographs were made using a digital camera (Olympus model C5060, Japan) attached to a light microscope (Olympus model BX50F, Japan). Illustration of the specimens’ habit was obtained using a HewlettPackard high-resolution scanner. The taxonomic characters commonly used for Scinaia species identiWcation (see Vroom and Abbott 2004; León-Cisneros et al. 2009) were evaluated for the studied material and the more stable and persistent ones were selected for Azorean species segregation, namely, shape and arrangement of utricles in surface Helgol Mar Res (2011) 65:111–121 view; shape of utricles in transversal view; spermatangium organization; rhizoidal Wlaments on the cystocarp; and structure of the fusion cell. A dichotomous key to the species from the Azores archipelago was constructed. The systematic arrangement, including the ordinal and lower classiWcation schemes, mainly follows Huisman (2006). The nomenclature used follows Guiry and Guiry (2009). Results On the basis of the combination of the selected diagnostic characters and comparison with type specimens and herbaria material, three species of Scinaia were identiWed for the Azores (Table 1): S. acuta (Figs. 2, 3, 4), S. furcellata (Figs. 5, 6, 7) and S. interrupta (Figs. 8, 9, 10), see key below. Key to the species of Scinaia from the Azorean archipelago 1a Utricles in surface view with a polygonal appearance (Fig. 7b, c), cystocarp with rhizoidal Wlaments (Fig. 10) S. interrupta 1b Utricles in surface view with a rosette appearance (Figs. 3b, 6c), cystocarp without rhizoidal Wlaments (Figs. 4, 7) 2 2a Utricles in surface view displaying large and small polygonal to rounded cells (Fig. 3b); utricles widely obovate in transverse section (Fig. 3d) S. acuta 2b. Utricles in surface view displaying large rounded cells, surrounded by smaller angular cells (Fig. 6c); utricles ovoid to obovate in transverse section (Fig. 6e) S. furcellata Species accounts Scinaia acuta (Setchell) Wynne 2005: p. 227 (Figs. 2, 3, 4) Fig. 1 Collection sites of Scinaia in the Archipelago of the Azores. Graciosa Island: 1 Ponta Branca; 2 Filipe Bay. Pico Island: 3 Madalena channel; 4 Calheta do Nesquim. São Miguel Island: 5 Poços de São Vicente; 6 Porto de Santa Iria; 7 Maia; 8 Feteiras harbour; 9 Moaçor-Ponta Delgada; 10 Pranchinha Bay; 11 Belém Bay; 12 São Roque Islet; 13 Lagoa; 14 Pópulo beach; 15 Viteleiro; 16 Caloura. Santa Maria Island: 17 Restinga; 18 Malbusca 123 (...truncated)